Tool and a cutting insert for chip removing machining

Abstract

The invention relates to a cutting tool including a basic body and a cutting insert detachably connected to the basic body via an interface, which includes a pair of co-operating connecting surfaces in which engagement means are included, which may be in the form of knobs and seatings. A knob and a co-operating seating have a rotationally symmetrical, conical shape to prevent translation of the cutting insert in the plane of the interface. Another knob ensures that the cutting insert cannot be rotated in relation to the conical knob. Simultaneously, ample bearing surfaces abut against co-operating support surfaces in a connecting surface. In such a way, the cutting insert is fixed in a stable, non-overdetermined position in the basic body. Furthermore, the invention relates to a cutting insert as such.

Description

[0001]This application claims priority under 35 U.S.C. § 119 to Sweden Patent Application No. 0600876-7, filed on Apr. 20, 2006, the disclosure of which is incorporated by reference herein in its entirety.FIELD OF THE INVENTION[0002]The present invention relates generally to a tool for chip removing machining of the type that includes a basic body and a cutting insert, which is detachably connected to the basic body via an interface, which includes, on one hand, a first connecting surface included in the basic body and in which one or more female- and / or male-like, primary engagement means are formed, and, on the other hand, a second connecting surface included in the cutting insert and in which one or more secondary, male- and / or female-like engagement means are formed for the engagement with the primary engagement means in the first connecting surface, the connecting surfaces of the cutting insert and the basic body having a common geometrical reference locus, and the cutting inse...

AI Technical Summary

Benefits of technology

The present invention provides a cutting tool with an improved interface between the basic body and cutting insert, which fixes the cutting insert stably in relation to the basic body and absorbs cutting forces in the area of the corner of the cutting insert. The interface includes a pair of engagement means that prevent translation and rotation of the cutting insert. The cutting insert can be manufactured by direct pressing without expensive grinding operations. The invention provides a triple securing of the cutting insert by preventing displacement, rotation, and translation. The invention is particularly suitable for indexable cutting inserts with multiple knobs.

Problems solved by technology

This means that the active edge of the cutting insert very well may end up in the desired position if the outcome of the insert production is good, but when the insert production is not good (so far that the cutting insert has swollen and become longer, or shrunk and become shorter, than intended), the position of the cutting edge in relation to the basic body may deviate to such a high extent from the desired position that the machining precision will be reduced.

However, in practice, the stability and position of the cutting insert are affected by a number of unforeseeable factors, one of the most difficult to master being the varying outcome of the manufacture of the cutting inserts.

As long as the outcome gives a good, nominal dimensional accuracy, the intended and calculated surface or line contact, among other things, is obtained between the flanks of the ridges and grooves along the entire length of the flanks, but as soon as even moderate form defects arise, there is a risk that the contact between the flanks is reduced to point contacts or partial line contact.

This may in turn result in the cutting insert, initially as well as during operation, being positioned incorrectly in relation to the basic body (by so-called overdetermination), and that the transfer of force between the cutting insert and the basic body becomes inferior.

However, in these cases, the female-like engagement means are only partly round seatings or seating surfaces, which are open laterally, and which therefore cannot absorb lateral displacement forces in arbitrary radial directions.

In practice, however, the screw lacks the capability of rotation-securing the cutting insert in a position in which the active cutting edge of the cutting insert reliably can retain an exact space position in relation to the basic body, since the screw, via the male thread thereof, has a certain play in relation to the female thread of the basic body, and may as well be deflected by the cutting forces.

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